Updates following hashbrown's inclusion in std

Cargo.toml

@@ -29,14 +29,14 @@ log = "0.4"
 quick-xml = { version = "0.14", default-features = false }
 num-format = { version = "0.4", default-features = false }
 str_stack = "0.1"
-hashbrown = "0.2"
 rand = "0.6.5"
 structopt = { version = "0.2", optional = true }
 env_logger = { version = "0.6.0", optional = true }
 rgb = "0.8.13"
 lazy_static = "1.3.0"
 fnv = "1.0.3"
 itoa = "0.4.3"
+indexmap = "1.0"
 
 [dev-dependencies]
 pretty_assertions = "0.6"

src/collapse/dtrace.rs

@@ -1,5 +1,5 @@
 use super::Collapse;
-use hashbrown::HashMap;
+use fnv::FnvHashMap;
 use log::warn;
 use std::collections::VecDeque;
 use std::io;
@@ -24,7 +24,7 @@ pub struct Folder {
     stack: VecDeque<String>,
 
     /// Number of times each call stack has been seen.
-    occurrences: HashMap<String, usize>,
+    occurrences: FnvHashMap<String, usize>,
 
     /// Keep track of stack string size while we consume a stack
     stack_str_size: usize,
@@ -115,7 +115,7 @@ impl From<Options> for Folder {
     fn from(opt: Options) -> Self {
         Self {
             stack: VecDeque::default(),
-            occurrences: HashMap::with_capacity(512),
+            occurrences: FnvHashMap::with_capacity_and_hasher(512, fnv::FnvBuildHasher::default()),
             cache_inlines: Vec::new(),
             opt,
             stack_str_size: 0,

src/collapse/perf.rs

@@ -1,5 +1,5 @@
 use super::Collapse;
-use hashbrown::HashMap;
+use fnv::FnvHashMap;
 use log::warn;
 use std::collections::VecDeque;
 use std::io;
@@ -71,7 +71,7 @@ pub struct Folder {
     cache_line: Vec<String>,
 
     /// Number of times each call stack has been seen.
-    occurrences: HashMap<String, usize>,
+    occurrences: FnvHashMap<String, usize>,
 
     /// Current comm name.
     ///
@@ -160,7 +160,7 @@ impl From<Options> for Folder {
             skip_stack: false,
             stack: VecDeque::default(),
             cache_line: Vec::default(),
-            occurrences: HashMap::with_capacity(512),
+            occurrences: FnvHashMap::with_capacity_and_hasher(512, fnv::FnvBuildHasher::default()),
             pname: String::new(),
             event_filtering: EventFilterState::None,
             opt,

src/differential/mod.rs

@@ -1,4 +1,4 @@
-use hashbrown::HashMap;
+use fnv::FnvHashMap as HashMap;
 use log::warn;
 use std::fs::File;
 use std::io;
@@ -46,7 +46,7 @@ where
     R2: BufRead,
     W: Write,
 {
-    let mut stack_counts = HashMap::new();
+    let mut stack_counts = HashMap::default();
     let total1 = parse_stack_counts(opt, &mut stack_counts, before, true)?;
     let total2 = parse_stack_counts(opt, &mut stack_counts, after, false)?;
     if opt.normalize && total1 != total2 {

src/flamegraph/attrs.rs

@@ -1,11 +1,12 @@
 use fnv::FnvHashMap;
+use indexmap::map::Entry;
 use log::warn;
-use std::collections::hash_map::Entry;
-use std::collections::HashMap;
 use std::fs::File;
 use std::io::{self, BufRead, BufReader};
 use std::path::PathBuf;
 
+type AttrMap<K, V> = indexmap::IndexMap<K, V, fnv::FnvBuildHasher>;
+
 macro_rules! unwrap_or_continue {
     ($e:expr) => {{
         if let Some(x) = $e {
@@ -18,7 +19,7 @@ macro_rules! unwrap_or_continue {
 
 /// Provides a way to customize the attributes on the SVG elements for a frame.
 #[derive(PartialEq, Eq, Debug, Default)]
-pub struct FuncFrameAttrsMap(HashMap<String, FrameAttrs>);
+pub struct FuncFrameAttrsMap(FnvHashMap<String, FrameAttrs>);
 
 impl FuncFrameAttrsMap {
     /// Parse frame attributes from a file.
@@ -101,7 +102,7 @@ pub(super) struct FrameAttrs {
     /// If set to None, the title is dynamically generated based on the function name.
     pub(super) title: Option<String>,
 
-    pub(super) attrs: FnvHashMap<String, String>,
+    pub(super) attrs: AttrMap<String, String>,
 }
 
 impl FrameAttrs {
@@ -211,8 +212,8 @@ mod test {
         let s = vec![foo, bar].join("\n");
         let r = s.as_bytes();
 
-        let mut expected_inner = HashMap::new();
-        let foo_attrs: FnvHashMap<String, String> = convert_args!(hashmap!(
+        let mut expected_inner = FnvHashMap::default();
+        let foo_attrs: AttrMap<String, String> = convert_args!(hashmap!(
             "class" => "foo class",
             "xlink:href" => "foo href",
             "target" => "foo target",
@@ -232,7 +233,7 @@ mod test {
             },
         );
 
-        let bar_attrs: FnvHashMap<String, String> = convert_args!(hashmap!(
+        let bar_attrs: AttrMap<String, String> = convert_args!(hashmap!(
             "class" => "bar class",
             "xlink:href" => "bar href",
             "aextra1" => "foo",